JPH0655841B2 - Fluorine-containing polymer film and its formation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention can provide a product having high hardness, excellent abrasion resistance, adhesion resistance, and abrasion resistance, low sliding resistance, and conductivity. The present invention relates to a fluorine-containing polymer film and a method for forming the same.

[Conventional technology]

Fluorocarbon resins have excellent heat resistance and chemical resistance, and are used for packing, sealing materials, etc., and also for sliding materials such as bearings by taking advantage of lubricity and non-adhesion. Especially as mechanical parts, polytetrafluoroethylene (PTF
E) and fluorinated graphite have been attracting attention, and in addition to using the fluorinated graphite as a simple substance, a method of using it in combination with another lubricant having a function not found in these substances is also being investigated. It is industrially very meaningful to coat these materials on the surfaces of mechanical parts, tools and the like. For example, for PTFE, film formation by a high-frequency sputtering method has been studied, but for fluorinated graphite, it has only been used as a lubricant additive, and research on a coating method has not progressed.

[Problems to be Solved by the Invention] The physical properties of the PTFE sputter film are different from those of the base material, and it is presumed that this is because the structure of the film itself is different from that of the base material itself. Regarding the frictional characteristics, the spatter film has a lower lubricity than the base material, and the hardness is low, and the film breaks and peels from the base material easily, so it is a stable lubricating film. It has the drawback of not working. Next, regarding the electrical characteristics, the resistance of the sputtering film is 10 ⁴ times smaller than that of the base material itself, but it is an insulator and cannot be used in applications requiring lubricity and conductivity. Atsuta

An object of the present invention is to provide a fluorine-containing polymer film having improved hardness, electric conductivity and lubrication characteristics by improving the low hardness, wear resistance and electric conductivity, which are drawbacks of conventional polymer films, and a method for forming the same. To provide.

[Means for solving problems]

Briefly describing the present invention, the first invention of the present invention relates to a fluorine-containing polymer film, in which a fluorine-containing olefin bond is present in the polymer. Is characterized by.

A second invention of the present invention is an invention relating to the method for forming a fluorine-containing polymer film of the first invention, wherein the fluorine-containing resin having an ether bond is added to the sputtering resin, plasma polymerization, ion beam or It is characterized by including a step of performing an ionization vapor deposition process.

The fluorine-containing polymer film of the present invention has a fluorinated olefin bond (for example, -C = CF or-) in the polymer as described above.
CF = CF-) is present, and optionally a perfluoroalkyl group and / or an olefinic bond is also present. Therefore, the film is excellent in conductivity, high hardness and lubricity. In that respect, there is a big difference in that the molecular structure is different from that of the polymer film obtained by the conventional technique, and a film having the conventional lubricity, hardness, and conductivity can be obtained.

Regarding the film forming method, in addition to the high frequency sputtering method, the fluorine-containing polymer material is introduced into a thin forming container in a gaseous or solid state, and another dry process such as a plasma CVD method, an ion beam method, or an ionization deposition method is used. By means of this, film formation is also possible.

Further, as the method for forming the polymer film, in addition to forming the film in the container as described above, the film can be formed by a conventionally used coating film forming method or casting method.

〔Example〕

Hereinafter, the present invention will be described more specifically by way of examples, but the present invention is not limited to these examples.

Example 1 FIG. 1 shows a schematic diagram of an example of an apparatus using a high frequency sputtering method as an example of a method for forming a fluorine-based polymer film according to the present invention. In FIG. 1, reference numeral 1 is a vacuum container, 2 is a substrate holder, 3 is a substrate, 4 is a target, 5 is a plate-shaped disk for receiving a target, 6 is a shutter, 7 is a high-frequency electrode, 8 is a matching box, and 9 is a box. High frequency power source, 10 is an oil diffusion pump, 11 is an oil rotary pump, 12 is a main valve, 13 is a roughing valve, 14 is an oil diffusion pump suction valve, 15 is a gas introduction variable valve, 16 is an argon cylinder, and 17 is It is a heater. The substrate 3 is placed on the substrate holder 2 in the vacuum container 1 and the perfluoropolyether (hereinafter,
(Abbreviated as PFPE) (oil) or PTFE / PFPE
(Grease-like) (all made by Montefluose Co., Ltd.) target 4 is put in a dish-shaped disc (made of PTFE) 5 and set. After the oil rotary pump 11 is warmed up for 5 minutes and rotated, the roughing valve 13 is opened to start exhausting. When the pressure reaches about 10 ^-2 Torr, the valve 13 is closed and the suction valve 14 for the oil diffusion pump is opened.
Is operated to open the main valve 12 to continue evacuation, and in parallel with this, the entire vacuum container is heated for 2 hours using the heater 17 in order to improve the evacuation efficiency. When the degree of vacuum rises to 10 ^-6 Torr, the variable valve 15 for gas introduction is opened to introduce argon gas, and the pressure is set to about 10 ^-3 Torr. A high frequency power supply 9 applies a high frequency voltage of 1 k to 2.5 kV to generate plasma. The input power is set to 100W to 250W by the matching box 8 and the main valve 12
Adjust the gas pressure in the vacuum vessel to about 10 ^-2 torr,
3 target spatter cleaning with Ar ⁺ ions
Do 0 minutes. After that, the shutter 6 is opened to form a film on the substrate. The high-frequency voltage, the applied power, and the gas pressure in the vacuum container are set under the same conditions as in the target sputtering, and the film formation time is 30 minutes. From the infrared (IR) absorption spectrum and the X-ray photoelectron spectroscopy (XPS) spectrum, it is clear that the fluorine-containing polymer film obtained by the above method contains an olefin bond in addition to the perfluoroalkyl group. It became. From the XPS spectrum, the content ratio of perfluoroalkyl group: olefin is 23:77 for the one using PFPE as the target (hereinafter abbreviated as PFPE film), PT
Using FE / PFPE (hereinafter referred to as PTFE / PFPE
It is 48:52 in abbreviated as "membrane". The physical properties of the obtained film are described below. As electrical characteristics, PFPE
The film has a structure in which conjugated olefin is present in the film to a large extent, and the band gap is small, so that the contact electric resistance is extremely small, and the P
While the TFE film and the PTFE / PFPE film are subject to charge-dipping and the peak binding energy value is largely shifted, this film does not show the shift (Table 1), which indicates that it is a conductive film.

Next, the result of the hardness test is shown in FIG. That is, FIG. 2 is a graph showing the results of hardness tests of various spatter films using a Vitzkers hardness meter as a relationship between load (N, horizontal axis) and hardness (Hv, vertical axis). In FIG. 2, Si is a silicon wafer,
HMV900 is a standard piece. As shown in FIG. 2, the hardness of the PFPE film and the hardness of the PTFE / PFPE film are considerably higher than those of the PTFE film. Finally, FIGS. 3 to 5 show the frictional characteristics in vacuum and in the atmosphere in the circumferential swing motion. That is, FIGS. 3 to 5 show PTFE and PTFE / PF, respectively.
5 is a graph showing the frictional characteristics of PE and PFPE various spatter films by the relationship between the number of times of circumferential oscillation (horizontal axis) and the coefficient of friction. P
The TFE film does not show stable friction characteristics even in the atmosphere and vacuum because the film is easily peeled and adhered. Next, both the PFPE film and the PTFE / PFPE film according to the present invention show stable friction characteristics with a relatively small value of 0.2 or less in the friction coefficient up to about 1000 times in the atmosphere. It is presumed that the lubricity of the PTFE / PFPE film in vacuum is deteriorated because the gas adsorbed by olefin was removed. After the friction test,
The friction marks of the ball indenter rubbed against the film were examined with a microscope.
Corresponding to the hardness test results, shearing of the membrane and adhesion of the membrane to the spherical indenter were observed for the soft membrane PTFE membrane. On the other hand, regarding the hard film PTFE / PFPE film,
Fracture of the membrane and adhesion of the membrane to the spherical indenter were hardly seen. From the above, the friction mechanism of this film is considered to be slipping at the interface between the spherical indenter and the film, and the film itself is hardly damaged. Furthermore, by changing the mixing ratio of PFPE and PTFE, the abundance ratio of perfluoroalkyl group and olefin is changed in the film, and the electric conductivity, hardness,
It is possible to control the lubrication characteristics, and it can be applied to a wide range of applications where various characteristics are required.

〔The invention's effect〕

As described above, according to the present invention, since a lubricating film having stable frictional properties and also having a function of conductivity or high hardness is obtained, these are conductive and have an adhesive property. It is useful as a surface treatment material for electrical mechanical parts such as switches, motors, magnetic disks, and magnetic tapes because of its small hardness and large hardness.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing the constitution of an example of a device for forming a fluorine-containing polymer film according to the present invention, and FIG. 2 is a graph showing the results of hardness tests of various spatter films using a Vickers hardness tester. ,
3 to 5 show PTFE, PTFE / PFPE, and
It is a graph which shows the friction characteristic of PFPE various sputter films. 1: Vacuum container, 2: Substrate holder, 3: Substrate, 4: Target, 5: Disc-shaped disc into which target is placed, 6: Shatter, 7: High frequency electrode, 8: Matching box, 9:
High frequency power supply, 10: Oil diffusion pump, 11: Oil rotary pump, 12: Main valve, 13: Roughing valve, 14:
Suction valve for oil diffusion pump, 15: Variable valve for gas introduction, 16: Argon cylinder, 17: Heater

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-54-56671 (JP, A) JP-A-55-99932 (JP, A) JP-A-61-120836 (JP, A)

Claims (2)

[Claims] 1. A fluorine-containing polymer film in which a fluorine-containing olefin bond is present in the polymer. 2. A method for forming a fluorine-containing polymer film in which a fluorine-containing olefin bond is present in a polymer, wherein a fluorine-containing resin having an ether bond is subjected to sputtering, plasma polymerization, ion beam or ionization deposition treatment. A method of forming a fluorine-containing polymer film, which comprises the step of: